To improve excavation and sediment guide performance of the lower surface of a concentrical enlarged disc provided at the lower end of a steel pipe casing and/or a concrete pole.
The ground excavation equipment has a bottom plate 3 having a diameter larger than the outer diameter of a casing 1 at the lower end of the excavation casing 1 and/or its inner concrete pole 2, and is provided with downward tilting blades 5 and upward tilting blades 6 directed toward the rotational direction of the casing and/or the concrete pole 2 via the cut-out parts 4 formed in the large diameter part 3'. A downward central excavation blade 7 is protruded at the lower face central part of the bottom plate 3, and a spiral excavation blade 8 in a trapezoid vertical cross section moving from the side face of the central excavation blade 7 to the outer periphery of the casing 1 is fixed to the lower face of the bottom plate 3.
| JPS53142901 | METHOD OF ACCURATELY LAYING PILOT HOLE IN GROUND |
| JPH09209676 | DRILLING VEHICLE |
| JPH0758027 | [Title of the Invention] A rod for excavating a pile hole |
Nobutaka Fujii
Shigeo Fujii